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R Frei

Publications and source records attributed to R Frei.

25 records · Page 2Linked to original sources

Use of ciprofloxacin in the treatment of Pseudomonas aeruginosa infections.

The therapeutic efficacy and safety of ciprofloxacin was studied in 30 patients with Pseudomonas aeruginosa infections. In 20 patients ciprofloxacin was given alone and in 10 patients (including 8 compromised hosts) in combination with an aminoglycoside (9) or azlocillin (1). Ciprofloxacin was given in doses of 500 mg orally or 200-300 mg i.v. every 12 h. In patients receiving only ciprofloxacin clinical cure with eradication of bacteria was obtained in 15 patients (75%) with infections of bone and joint (6), skin and soft tissue (4), lung (2), middle ear (2) and CSF (1). Two patients with lymphoma and Pseudomonas aeruginosa pneumonia died. In patients receiving combination therapy a definite therapeutic success was achieved in four (40%). Three patients with Pseudomonas aeruginosa septicemia died. In seven patients nine bacterial strains with decreasing susceptibility of ciprofloxacin (increase in MIC from less than or equal to 0.5 micrograms/ml to 2-16 micrograms/ml) were selected (6 Pseudomonas aeruginosa, 1 Enterobacter cloacae, 1 Serratia marcescens, 1 Staphylococcus aureus). Ciprofloxacin was well tolerated. This new quinolone seems to be suitable for single drug treatment of Pseudomonas aeruginosa infections in patients with normal host defense mechanisms, while its therapeutic potential in compromised hosts requires further evaluation.

Administration, Oral

Fatal Legionella pneumophila pneumonia: treatment failure despite early sequential oral-parenteral amoxicillin-clavulanic acid therapy.

A 68-year-old male, having just returned from a two-week holiday on the Island of Ischia, developed unilateral pneumonia for which he was treated with oral amoxicillin-clavulanic acid and hospitalized within three days when the disease worsened and spread to both lungs. Despite parenteral amoxicillin-clavulanic acid (up to 2.2 g i.v. t.i.d.) the pneumonia spread rapidly over the next three days. Sputum cultures returned post mortem yielded Legionella pneumophila serogroup 1 and urine tests revealed the presence of Legionella antigen. Disk diffusion susceptibility testing on BCYE of the causative pathogen revealed zone diameters of inhibition of the clinical isolate exceeding 50 mm, indicating high susceptibility to this antibiotic combination. The therapeutic failure of amoxicillin-clavulanic acid should stimulate further reports and studies on the efficacy against legionellosis of this drug and similar beta-lactam inhibitor combinations as well as other beta-lactamase-stable beta-lactams.

Administration, Oral

In vitro susceptibility of 33 clinical case isolates of Xanthomonas maltophilia. Inconsistent correlation of agar dilution and of disk diffusion test results.

Xanthomonas maltophilia is an emerging nosocomial pathogen, possibly selected by a changing antimicrobial usage and patient population. In the present study, we tested the susceptibility of 33 recent clinical case isolates to 12 commonly employed antimicrobials. Trimethoprim-sulfamethoxazole (1:19 ratio) and doxycycline were uniformly the most active agents; ciprofloxacin and fleroxacin were slightly less active and, along with tetracycline and ceftazidime, more variable in their potency. Interestingly, the disk diffusion method routinely overstated the activity of ciprofloxacin (12% very major errors, 58% minor errors). The present in vitro data and the hitherto accumulated clinical experience suggest that in the absence of unequivocal clinical efficacy of ciprofloxacin against this increasingly recognized nosocomial pathogen, the decision to use ciprofloxacin or any other fluoroquinolone against these pathogens should rely preferentially on the dilution susceptibility test method results. In contrast, the present study confirms the excellent predictive value of trimethoprim-sulfamethoxazole, tetracycline, and fleroxacin disks as well as the higher (9% minor errors) inhibitory activity of these drugs. Hence, pending the elaboration of clinical efficacy data of alternative antimicrobial agents against X. maltophilia infections, trimethoprim-sulfamethoxazole remains a sound therapeutic choice.

4-Quinolones

Outer membrane permeability and beta-lactamase content in Pseudomonas maltophilia clinical isolates and laboratory mutants.

Low outer-membrane permeability appears to be responsible for the generally high degree of antibiotic resistance of Pseudomonas maltophilia. Constitutive overproduction of beta-lactamases affects the sensitivity of these bacteria only to those beta-lactam antibiotics that are hydrolyzed by strain-specific beta-lactamases and that do not efficiently induce these enzymes in inducible strains.

Anti-Bacterial Agents